REAL Eggs: Not all proteins are created equal

Formulators and consumers alike are sorting out the facts about different protein types as it receives mounting media and public attention. With good reason — protein impacts overall nutrition and can contribute to everyday fitness. As an ingredient, the right protein also supplies both flavor and functionality. Egg ingredients can be the perfect protein choice.

Long a favored nutrient of athletes and fitness buffs, mainstream America is turning to protein more than ever. Package labels point out for consumers the protein content of products, ranging from breakfast foods to desserts and beverages. According to Mintel data, yogurt led all other product types in 2014 for high-protein package label claims, but cereal, pasta, packaged vegetables and even ice cream also promote protein content. Even fast food establishments are jostling for the protein market share.1

Protein can be measured by two standards; its nutritional quality and its functional properties. Formulators must carefully consider the nutritional aspect of a protein source as well as its functional properties, as protein can be either beneficial or detrimental to product shelf life, texture and taste.

Protein and Beyond

The six grams of high-quality protein that one large egg supplies is just the beginning of an egg’s nutritional story. At 70 calories, one large egg provides 13 vitamins and minerals, including the antioxidants lutein and zeaxanthin2 and it’s one of the few food sources of vitamin D, identified in 2010 by the Dietary Guidelines Advisory Committee as a nutrient of concern.

This complement of vitamins and minerals relative to its calorie count makes the egg a nutrient-rich (nutrient-dense) food or ingredient. Whether egg ingredients play a major or minor role in product applications, the nutrient content of each individual ingredient in a product can impact the final label statement. Ingredients must be selected carefully and with the final label statement in mind.

The importance of proper ingredient selection and application composition is highlighted by the fact that today’s companies grapple with the paradoxical dilemma of supplying food to a consumer population that sometimes struggle with a combination of food insecurity, malnutrition and obesity.3 Various studies link food insecurity with obesity. Consumers might not be eating nutrient-dense foods that supply a proper balance of vitamins and minerals.4, 5

High-quality protein, nutrient-rich ingredients such as eggs can help create food products that provide nutrition benefits for consumers. With protein popularity at an all-time high, and indicators pointing to a segment that will continue to grow, companies can take advantage of this window of opportunity.

Protein’s Popularity

According to Mintel, the U.S. is the largest market for high-protein products worldwide.6 For example just one product category, high-protein bars, exhibited astonishing growth with launches from 2012-2013 up 126.9 percent over the previous year.

NPD Group data shows that 62 percent of consumers make a conscious effort to consume protein, yet 71 percent don’t know how much their body requires.7 With a number of protein sources and products available, there is sure to be confusion about which is most effective.

Proteins Are Not Created Equal

Protein is a macronutrient, like fats and carbohydrates, and provides a source of calories, or energy for the body. Protein is found in every cell in the body. It supplies energy, can boost satiety, help prevent muscle loss in older adults, and can aid athletes build muscle recovery time after workouts. Amino acids, commonly referred to as the “building blocks of protein,” perform much of the work credited to protein. The amino acid composition of a protein determines the quality of different types of proteins.

Amino acids are classified as either essential or nonessential. The body cannot produce essential amino acids (EAA), identified as histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan and valine, so they must be obtained through the diet. The protein in eggs is highly digestible and provides much of the essential amino acids.

In virtually every method used to evaluate protein quality and digestibility, egg proteins consistently rank highly with milk proteins.8

Satiety and Weight Management

Satiety and hunger management are key components to controlling weight. Multiple scientific studies provide evidence to support protein’s benefits for increasing and maintaining weight loss resulting from appetite regulations and energy expenditure.9 A breakfast high in -protein — specifically one that includes eggs — helps curb hunger throughout the day. When dieters eat a breakfast high in protein it can help promote greater weight loss than a carbohydrate-based breakfast that contains the same number of calories.10, 11

The biological value (BV) of a protein might be a contributing factor in determining protein’s effect on appetite. One study compared a cereal breakfast to an egg breakfast. The cereal breakfast scored a BV of 42, while eggs scored a BV of 100. Study participants who ate the egg breakfast said they felt more satiated. The egg group had lower blood levels of ghrelin, a hormone that signals hunger and significantly higher levels of PYY, a hormone that signals fullness, compared to the cereal group.12

Consuming breakfast has been associated with better diet quality and greater nutrient intake, compared to skipping breakfast,13 as well as a possibly beneficial effect on appetite control and satiety.14 Specifically, eggs as a breakfast food have been found to be effective at increasing satiety and reducing subsequent energy intake.15 Skipping breakfast, on the other hand, has been linked to an increased risk of type 2 diabetes.16 However, some studies have found consuming breakfast to have no significant effect on weight.17,18 While consuming breakfast, especially one that includes a high-quality protein, such as that found in eggs, contributes to diet quality, more research is needed to know if regular consumption of the morning meal results in improved weight management via appetite control.

Consumers are aware of the satiating effect of protein. Within the International Food Information Council 2014 Food & Health Survey, 91 percent of consumers agree it is important to get enough protein in the diet and 72 percent agree with the statement ‘it helps people to feel full (satiety).’ Among those trying to consume protein, four out of five get it from poultry, eggs, nuts, seeds and fish, with 85 percent of that group selecting eggs as one of their protein choices.19

Protein at Every Meal

Most Americans eat approximately three times more protein at dinner than at breakfast. Studies suggest, however, that, protein intake should be spread out over the day, with 25-30 grams of high-quality protein provided at each meal.

A recent study used a seven-day crossover feeding designed to measure changes in muscle protein synthesis related to meals with an evenly spread protein intake compared to a diet that skewed protein intake towards the evening meal. The result was a 25 percent increase in muscle protein synthesis in those consuming protein evenly spread over meals. Overall, the authors indicated, “Unlike fat or carbohydrates, the human body has limited capacity to transiently store ‘excess’ dietary protein from a single meal to acutely stimulate muscle protein anabolism at a later time.”20

Benefits of Protein-Rich Diets

Protein distribution and protein intake become even more important with age. Decreased calorie intake is common in older adults, and on average, they consume fewer calories and less protein than younger adults.21 In fact, under-nutrition can be a complicating factor in elder care.22 In addition, there is a direct correlation between protein intake and muscle mass.

Sarcopenia is a progressive loss of muscle mass, function, quality and strength related to the aging process that affects23 an estimated 45 percent of older adults in the United States. As the population of adults age 60 and above continues to grow, with global estimates that this group will triple by 2050, including a large subset of individuals over the age of 85,24 experts warn that sarcopenia will become even more common. Loss of muscle mass leads to diminished strength and can contribute to falls and fractures, frailty and loss of physical function. After age 70, muscle loss accelerates to approximately 15 percent per decade.25

Further complicating the issue, adults above age 60 exhibit anabolic resistance, which means they do not respond to protein and exercise in the same manner as younger adults.26 A combination of increased protein plus exercise is critical for proper muscle retention.27 In addition, researchers note that formulators need to take into account the sensory preferences of an aging population related to loss of smell, taste and an increase in dysphagia28 or trouble swallowing.

In a presentation delivered at an Institute of Medicine Food Forum in Washington, D.C., in 2010, Jim Kirkwood of General Mills, “Formulating for Aging Boomer Consumers,” identified several key aspects of food formulating product developers need to keep in mind. Under texture and appeal, he said sensory consideration include “vibrancy, potency and consistency.” Vibrancy relates to appearance or mouthfeel. Potency refers to a “taste profile that is the ‘sweet spot’ for older adults, given that the sense of taste changes with ageing.” And Consistency refers to the food’s texture and the need to develop foods that are not, for example, too crunchy or hard.”29 An egg contains high-quality protein that is easily digestible, blends well with a wide variety of flavors and depending on preparation, can lend a texture that will meet the sensory challenges of an aging population.

A high-protein diet also might help lower the risk for developing high blood pressure. A study published in the American Journal of Hypertension30 found that participants consuming the highest amount of protein (an average of 100 g protein/day) had a 40 percent lower risk of developing high blood pressure (HPB) compared to those consuming the least. Further, the researchers found that adults who consumed more protein, whether from animal or plant sources, had significantly lower systolic blood pressure and diastolic blood pressure levels after four years of follow up.

Protein’s Practical Side

In addition to its nutritional benefits, egg protein has a practical side. Proteins are available in different forms and different proportions within the white and the yolk, but both can contribute valuable properties to formulations. The white is the albumen, containing 56 percent of the total protein in an egg. Yolks contain slightly less than half the egg’s protein, vitamins and minerals, and the lipid components.

The category of prepared meals has witnessed an increase in the number of breakfast offerings, with handheld sandwiches and breakfast bowls gaining popularity and corresponding shelf space. Preformed egg patties or egg scrambles are an obvious choice for many of these applications as a visible, primary protein, however egg ingredients contribute more subtle benefits in other prepared meals.

The egg white proteins’ coagulative properties provide structure to noodles to help maintain a desirable texture and bite when held in a liquid or high-moisture frozen medium. Coagulation helps bind other ingredients together. Egg proteins help batters and breadings adhere to a substrate in an appetizer application, or hold seeds, grains and other decorative elements onto the outside of breads and rolls, for example.

Egg ingredients, primarily lipids, form emulsions consisting of very fine droplets, which help sauces maintain a pleasant mouthfeel. The right selection of egg ingredient for a sauce application will help it maintain appearance, texture and viscosity under high-heat — desirable attributes in a product designed for microwave heating.

Nutrient Density

The concept of evaluating a food’s nutrient density, especially in context with sustainability, is relatively new. As one researcher noted, “The American diet is said to be increasingly energy-rich but nutrient-poor.” Yet, there is a lack of consistent standards or criteria for measuring nutrient density. One study said, “In many cases, healthful foods are defined by the absence of problematic ingredients — fat, sugar and sodium — rather than by the presence of any beneficial nutrients they might contain.”

A study published in 2014 compared the energy and nutrient density of foods in relation to their carbon footprint or greenhouse gas (GHG) score.1 While sugar, sweets and grains exhibited the lowest GHGs; these foods also offered the lowest nutritional value. The most nutrient-dense foods in the study had the highest GHG scores, however, they offered much higher nutritional value. Therefore, the parameters used to measure a food’s value related to its GHG score can vary widely depending upon whether the criteria used was a per weight basis, per energy or per nutrient content. Animal-based proteins typically offer a higher nutrient density than the plant-based foods used in the study, including sugar, which, on a weight basis, posts the lowest GHG score. The authors recommended further study saying, “Consideration of the environmental impact of foods needs to be linked to concerns about nutrient density and health.”

Proteins from egg whites help control crystallization in select confections and frozen foods. Crystallization impacts food quality and mouthfeel by lending a gritty texture to a substance that is supposed to be smooth and creamy. Many confections involve a super-saturated solution of sugar and water. While saturation is desired, if it occurs too quickly, crystallization will result. Egg white introduced as an interfering agent slows the process of saturation, forming finer crystals for a smooth, creamy texture. In ice cream, egg yolk disperses fat throughout the ice cream mix to prevent it from clumping. Eggs aid in whipping properties to help achieve desired overrun. And the combination of protein and fat present in eggs can help prevent the aggregation of crystal-forming compounds.

Baking with Eggs

Many baked goods owe their appearance, texture,
taste and part of their shelf life to egg ingredients.
Staling occurs when swollen starch chains lose
water content. Egg white proteins help trap extra
water and lend greater strength to the baking
structure. In formulations that use whole egg, the
yolk’s lecithin, a lipid, lodges in the space between
the highly branched starch chain to help hold water
and extend shelf life.

Egg white is comprised of conalbumin, globulins, ovalbumin and ovomucin; proteins which enable egg whites to create the largest food foams possible from a natural source — six to eight times greater in volume than the original liquid. Ovalbumin and ovomucin are primarily responsible for the formation, volume and structure of egg white foam. When heat is applied during baking, the proteins in the foam form a reinforced network that strengthens the baked good and enables it to maintain volume. Time, temperature and other variables can affect egg white foam stability.

Incredibly Flexible

The impressive list of functional benefits supplied by egg ingredients becomes even more incredible in light of the fact that eggs are a natural food. Whether including eggs in formulation for their nutritional contribution or their functional attributes, formulators can simply list them as “eggs” on the label. This is important as the push for more transparent, clean labeling intensifies. While companies are shying away from use of the word “natural,” consumers are increasingly interested in simple labels with natural ingredients. In fact, more than one research group has identified a shift from clean to “clear” labeling as a dominant industry trend, with clear focusing more on transparency within the supply chain and corporate sustainability practices.

In addition to the consumer trend for greater label transparency, other eating habits or preferences growing in popularity include flexitarianism and vegetarianism. Flexitarians are identified as those who have decided to include more vegetables in their diet and cut back on meat, not eliminate it. The vast majority of vegetarians who have eliminated meat will accept eggs as a viable protein option. Eggs can supply a valuable source of high-quality protein for vegetarian or flexitarian meals. According to Mintel, 12 percent of global new product launches in 2013 were labeled “vegetarian.” Yet, despite the popularity of protein, less than one percent of food and drink products launched globally carried both a “vegetarian” and “high-protein” claim.31

There will always be special market segments that can benefit from the protein eggs offer. Gluten free is predicted to grow through 2018 and eggs supply functionality in addition to supplementing protein lost when wheat flour is replaced with gluten-free alternatives. While eggs in the shell are naturally gluten free and are not a genetically modified (GM), or bioengineered food, formulators should check with their egg suppliers about the GM status of other ingredients that are sometimes added to egg products to enhance functionality.

Egg ingredients offer flexibility to manufacturers who are able to select from dried, liquid or frozen versions of whole eggs, egg yolk or egg white, depending on processing parameters and functional requirements. For example, applications such as breakfast sandwiches or bowls can use prepared egg products that have been scrambled, boiled, or formed into patties.